Connecter for firing explosive charges



Nov. 24, 1925.

N. C. COTABISH CONNECTER FOR FIRING EXPLOSIVE CHARGES File d Jan. 4, 1921 INVENTOR.

ATTORNEYS.

Patented Nov. 24, 1925.

FEW

UNZTEBL S it, at T ES iA'il'ENT @FFHQE.

NELSON C. COTABISH, E CLEVELAND, QHIO, ASSIGNOR TO NATIOEAL CARBON COM- PANY, INC., A CORTE'OBATIQN OF NEW YORK.

CONNECTER FOR FIRING EXPLCSIVE CHARGES.

Application filc l January 4, 1921.

To aZZ whom it may concern:

Be it known that I, Nansen G. GOTABISH, a citizen of the United States, residing at 13105 Det Ave, Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Connectors for Firing Explosive Charges, of which the following is a specification.

This invention relates to means for firing explosive charges and more particularly to an improved connecter or electrical switch means for connecting a source of current to an electric charge-firing device.

In firing explosive charges, as in mine blasting, for example, the electrical circuits of charge-firing devices have employed a single switch which has, at times, due to closure by faulty construction, carelessness or accident, caused premature explosions.

The primary object of this invent-ion is to provide an improved switch means which will more thoroughly safeguard charge-firing circuits and which may readily be coupled to types of electric batteries now on the market.

The above and other objects and the novel features of my invention will be apparent from the following description taken with the accompanying drawings which form a part of this application and in which Fig. 1 is a View, partly diagrammatic, illustrating a connector embodying my invention and its application in a charge-firing circuit,

Fig. 2 is a plan view of the connecter on an enlarged scale, and

Fig. 5;) is a longitudinal sectional view of one of the connecter arms, taken on the line of Fig. 2.

For purposes of illustration, the invention is herein shown as applied to a well known form' of low-tension cl1arge-1firing circuit comprising conductors L and L connected to a low-tension detonator or fuse F of any suitable or preferred construction embodying a high resistance wire that may be heated to iucandescence by electric current from a suitable battery B. It will be understood that the invention is also applicable to high-tension firing circuits, and other circuits for firing explosives. The flow of current to the fuse or firing device F is controlled by two normally open circuit closers S and S, which are arranged within reach of a single person so that they may be simul- Serial No. 434,971.

taneously but independently operated by him to fire the charge of explosive.

The normally open circuit closers S and S are ar 'anged as a part of the connecter device C by means of which the circuit conductors L and L are electrically connected to the positive and negative binding posts P and N of the battery B. The battery B may be of any suitable type, preferably a multi-cell battery that will give the desired amperage and voltage to fire the fuse. The connecter C may be of any suitable type, and as illustrated, comprises two relatively adjustable arms or plates A and A of suitable insulating material such as fiber or other composition adapted to provide rigid supporting means for the circuit closers S and S and associated terminals. The arms A and A may be pivotally con nected together at one end, as by a headed bolt D, and may be clamped in various adjusted positions by means of a nut M hearing against the outer side of one arm and having threaded connection with the threaded shank of the bolt D. The free ends of the arm A and A may be provided with suitable metal terminals T and T whereby the connecter may be mechanically and electrically coupled to battery terminal posts by the binding screws of the latter. The arms A, A also carry suitable binding devices, as spring metal clips K, K, respectively adapted to connect the wires Tl, L in circult with the switches i, S and terminals T, T. The terminals T, T; switches S, S and clips K, K may be arranged on the adjustable connecter arms in any suitable manner, but are desirably arranged in sets, as illustrated. Inasmuch as the arms A, A in this particular arrangement are substantially simi lar in construction, only the construction of the arm A will be described in detail.

The terminal T may consist of a metal plate provided. with a notch or recess whereby it may be readily applied to a battery terminal post. The terminal. T may be mounted on the arm A and connected in circuit with the switch S in any suitable manner, but as shown, is desirably secured in a central slot 11 at the free end of the insulating arm A by headed screws 12 which are threaded into a metal plate 15 set in the bottom face of the supporting arm. The conducting plate 15 is electrically connected to the terminal T through the screws 12, and a part of its upper face at one end, as at 151, is exposed in the switch cavity 16 where it is engageal'ile by the free end. of the spring metal switch member 17. The switch member 17 is normally open or out of contact with the plate 15 and may be depressed into contact with said plate, as by means of a push button 18 the outer end of which may be exposed at one face of the supporting arm A, but fiush therewith to prevent accidental depression of the switch member. The switch member 1' is electrically connected to the terminal. clip K, as by a conducting screw 19, which holds the said clip in place on the arm A. The insulating cover 20 of the switch cavity 16 has a metal bushing 21 set therein to which the fixed end of the switch member 1? is connected, and this bushing may also have threads to receive the threaded end of the screw 19 whereby the cover 20 is held in place. The clip K may be of any suitable form, and as illustrated, comprises a well known type ot sheet metal. device having two cooperating hook-shaped parts 22 and 23 to receive and clamp a wire or conductor between them.

The operation and manipulation of the connecter will be understood from the foregoing description and from the drawings. The arms A and A of the connecter may be spread apart the necessary distance to permit the terminals T and T to be coupled to the binding posts P and N of the battery. The nut M may then be tightened to clamp the arms in this position. Since the switches S and S are independently operable, if either of them is accidently closed, while the other switch is open, the charge will not be fired. It is necessary to simultaneously depress both circuit closers S and S to fire the charge and it will, therefore, be seen that by the present arrangement, pr unature explosions due to faulty switch construction or carelessness in operating the same will be greatly reduced.

While I have shown and described a desirable form of my invention in detail, it is to be understood that various changes may be made therein without departing from the spirit of the invention or sacrificing any of the advantages thereof.

I claim:

1. Electrical switch means for use in controlling'electrical circuits, said switch means comprising the combination of two independently operable circuit closers, terminals severally electrically connected to said circuit closers and adapted to be secured to the binding posts or terminals of a battery, and means supporting said terminals so they are adjustable relatively to one another.

2. A device for controlling circuits comprising, in combination, two normally open independently operable electric circuit closers, relatively adjustable arms, terminals adapted to be electrically connected to said circuit closers and mounted adjacent the ends of said arms and adapted to be electrically and mechanically coupled to the binding posts or terminals 01"- a battery.

3. A device for controlling circuits comprising the combination of two normally open independently operable electric circuit closers, means for supporting said circuit closers whereby one person may operate them simultaneously, and relatively adjustable terminals severally electrically connected to said circuit closers and adapted to be electrically and mechanically coupled to the binding posts or terminals of a battery.

e. A device for controlling circuits comprising the combination of two normally open independently operable electric circuit closers, pivotally connected relatively adj ustable arms upon which said circuit closers are -mounted so that such circuit closers may be operated simultaneously, terminals adjacent the free ends of said arms and severally electrically connected to said circuit closers and adapted to be electrically and mechanically connected to the binding posts or terminals of a battery.

5. A device for electrically connecting a battery in circuit with means for firing an explosive ciharge, said "device comprising the combination of a pair of pivotally connected arms of insulating material, means for retaining said arms in a predetermined adjusted relation, a terminal mounted at the free end of each arm and respectively adapted to be electrically and mechanically coupled to the binding posts or terminals of a battery, a normally open circuit closer on each of said arms and electrically con nected, respectively, to the aforesaid terminals, and means for electrically connecting conductors to said circuit closers.

6. A device for controlling electrical cir- Y NELSON O. COTABISH. 

